Bipack color
Encyclopedia
In bipack color photography in motion pictures, two strips of film are used to record two colors of the spectrum for the purpose of print later onto one strip of film. The technique of bipack color photography became economical in the early 1910s when Kodak introduced duplitized film
.
Bipack photography was, at one point in motion pictures, the most economical process of natural-color cinematography available, where color was needed and circumstances did not warrant the higher cost of three-color methods. By the late 1940s and early 1950s, with the introduction of "monopack" stocks such as Kodachrome
, Ansco Color, DuPont Color
, and Eastmancolor, bipack photography and printing dwindled.
Bipack color refers to the type of camera load that is used for the effect. Bipack
photography refers to two strips running through the camera at once, for the purpose of recording two different spectra of light, generally.
Color photography begins with any standard camera. Special magazines or adapters must be provided to accommodate two separate rolls of film. Two films are loaded, passing through the photographing aperture with the emulsions towards each other. The front film is orthochromatic
, to record the blue-green portion of the picture. On the surface of its emulsion is a red-dye layer equivalent to a Wratten 23A
filter. The rear film is panchromatic, and being photographed through the red coating of the front film, records only the red-orange components of the picture. No filtering is necessary either for exterior or interior photography, as all necessary color corrections are made by adjusting the development of the two negatives during printing.
Since the image must be focused on the plane of contact of the two negatives used, lenses and focusing screens used in bipack photography would be readjusted to throw the plane of focus .006" behind that of the standard black-and-white plane.
Care would be taken to avoid photographing objects of purple, lavender or pink coloring, as bipack color generally cannot reproduce these colors in printing.
After processing the two negatives, the red and cyan records were printed separately on a single strip of Eastman or DuPont duplitized stock. Since the red negative was reversed in camera (that is, its emulsion away from the lens), there was no optical printing required to focus the image, and thus contact printing on both emulsions took place. Both sides were toned
by floating each side in a tank with the complementary colors (cyan for the side exposed with the red negative and vice versa) using toning chemicals or through dye mordanting.
In addition, Consolidated Film also owned the Trucolor
color system, which was shot as bipack color, but processed with special duplitized stock produced by the Eastman Kodak company that carried a dye-coupler.
For the 1948 Summer Olympics
in London
, the Technicolor Corporation
devised a bipack color filming process—dubbed "Technichrome" -- whereby hundreds of hours of film documented the Olympics in color, without having to ship expensive and heavy Technicolor cameras to London.
Duplitized film
Duplitized film stock was a type of film available through various companies used in color photography and special effects. It was introduced in the early 1910s...
.
Bipack photography was, at one point in motion pictures, the most economical process of natural-color cinematography available, where color was needed and circumstances did not warrant the higher cost of three-color methods. By the late 1940s and early 1950s, with the introduction of "monopack" stocks such as Kodachrome
Kodachrome
Kodachrome is the trademarked brand name of a type of color reversal film that was manufactured by Eastman Kodak from 1935 to 2009.-Background:...
, Ansco Color, DuPont Color
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
, and Eastmancolor, bipack photography and printing dwindled.
How it works
Bipack
In cinematography, bipacking, or a bipack, is the process of loading two reels of film into a camera, so that they both pass through the camera gate together...
photography refers to two strips running through the camera at once, for the purpose of recording two different spectra of light, generally.
Color photography begins with any standard camera. Special magazines or adapters must be provided to accommodate two separate rolls of film. Two films are loaded, passing through the photographing aperture with the emulsions towards each other. The front film is orthochromatic
Orthochromatic
- Orthochromatic photography :Orthochromatic photography refers to a photographic emulsion that is sensitive to only blue and green light, and thus can be processed with a red safelight. The increased blue sensitivity causes blue objects to appear lighter and red ones darker...
, to record the blue-green portion of the picture. On the surface of its emulsion is a red-dye layer equivalent to a Wratten 23A
Wratten number
Wratten numbers are a labeling system for optical filters, usually for photographic use comprising a number sometimes followed by a letter. The number denotes the color of the filter, but is arbitrary and does not encode any information ; letters increase with increasing strength.They are named for...
filter. The rear film is panchromatic, and being photographed through the red coating of the front film, records only the red-orange components of the picture. No filtering is necessary either for exterior or interior photography, as all necessary color corrections are made by adjusting the development of the two negatives during printing.
Since the image must be focused on the plane of contact of the two negatives used, lenses and focusing screens used in bipack photography would be readjusted to throw the plane of focus .006" behind that of the standard black-and-white plane.
Care would be taken to avoid photographing objects of purple, lavender or pink coloring, as bipack color generally cannot reproduce these colors in printing.
After processing the two negatives, the red and cyan records were printed separately on a single strip of Eastman or DuPont duplitized stock. Since the red negative was reversed in camera (that is, its emulsion away from the lens), there was no optical printing required to focus the image, and thus contact printing on both emulsions took place. Both sides were toned
Film tinting
Film tinting is the process of adding color to black-and-white film, usually by means of soaking the film in dye and staining the film emulsion...
by floating each side in a tank with the complementary colors (cyan for the side exposed with the red negative and vice versa) using toning chemicals or through dye mordanting.
Bipack color processors
Over the years, a great number of bipack color processors existed, largely due to the lack of holding patents on processing in this method. These systems included:- KodachromeKodachromeKodachrome is the trademarked brand name of a type of color reversal film that was manufactured by Eastman Kodak from 1935 to 2009.-Background:...
(1915), Eastman-Kodak's first color system - PrizmaPrizmaThe Prizma Color system was a technique of color motion picture photography, invented in 1913 by William Van Doren Kelley and Charles Raleigh. Initially, it was a two-color additive color system, similar to its predecessor, Kinemacolor...
(1918–1928) - Brewster Color (1913-193?)
- MagnacolorMagnacolorMagnacolor was a color film process owned by Consolidated Film Industries. It was an off-shoot of William Van Doren Kelley's Prizma and utilized the same bi-pack color process. Magnacolor was succeeded at the company by Trucolor.-See also:*Bi-pack color...
(1928-194?), by Consolidated Film, a direct off-shoot of Prizma - Colorcraft (1929)
- Harriscolor (1929)
- MulticolorMulticolorMulticolor is a subtractive natural color process for motion pictures. Multicolor, introduced to the motion picture industry in 1929, was based on the earlier Prizma Color process, and was the forerunner of Cinecolor....
(1929–1932), a company financed by Howard HughesHoward HughesHoward Robard Hughes, Jr. was an American business magnate, investor, aviator, engineer, film producer, director, and philanthropist. He was one of the wealthiest people in the world... - Photocolor (1930)
- Sennettcolor (1930)
- DuPack Process (1932)
- CinecolorCinecolorCinecolor was an early subtractive color-model two color film process, based upon the Prizma system of the 1910s and 1920s and the Multicolor system of the late 1920s and 1930s. It was developed by William T. Crispinel and Alan M...
(1932–1954), the most popular bi-pack processor, an off-shoot of Multicolor - Polychrome
- Kesdacolor
- Douglass Color (second process)
- Dascolor
- Cinefotocolor
- Colorfilm process
In addition, Consolidated Film also owned the Trucolor
Trucolor
Trucolor was a process used and owned by Consolidated Film Industries division of Republic Pictures. Trucolor was originally a two-strip process based on the earlier work of William Van Doren Kelley's Prizma color process. It later became a three-color process.Republic used Trucolor mostly for its...
color system, which was shot as bipack color, but processed with special duplitized stock produced by the Eastman Kodak company that carried a dye-coupler.
For the 1948 Summer Olympics
1948 Summer Olympics
The 1948 Summer Olympics, officially known as the Games of the XIV Olympiad, were an international multi-sport event which was held in London, England, United Kingdom. After a 12-year hiatus because of World War II, these were the first Summer Olympics since the 1936 Games in Berlin...
in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, the Technicolor Corporation
Technicolor
Technicolor is a color motion picture process invented in 1916 and improved over several decades.It was the second major process, after Britain's Kinemacolor, and the most widely used color process in Hollywood from 1922 to 1952...
devised a bipack color filming process—dubbed "Technichrome" -- whereby hundreds of hours of film documented the Olympics in color, without having to ship expensive and heavy Technicolor cameras to London.
See also
- Color motion picture film
- Color photographyColor photographyColor photography is photography that uses media capable of representing colors, which are traditionally produced chemically during the photographic processing phase...
- List of color film systems
- List of film formats